Mechans - the OP’s inquiry did allow for observations about the individual preamps (i.e., "on their own"). Not owning a Van Alstine, I was only able to provide comparison to a 6H30-based preamp that I had found very satisfactory sound-wise.
wout31 has explained the single opening at the right end of the face of the Freya. I’ll add that along with 3 push buttons for mute, output and input selection and the volume knob, there are 9 LEDs: 1 for mute, 2 for output mode (JFET buffer mode or tube mode; none lit = passive mode), 5 for input selection (2 balanced; 3 SE), and a final LED to indicate remote control of volume. When this last is lit, the volume control knob is disabled.
wout - I hope you will be as pleased as I am with the Freya. Will be interested in hearing your thoughts about it.